Every BA/BE study is the same shape with different content. A sponsor wants their molecule's pharmacokinetic profile demonstrated against a reference. A CRO sets up a clinical phase, dosing, sample collection, bioanalytical quantification, statistical analysis, and a regulator-grade report. The architecture is fixed. What varies is which molecule, which formulation, which jurisdiction, which acceptance window. The thirteen stages below are what every BA/BE study runs through, in this order, every time.
/ 01The thirteen stages.
Project enquiry.
Before assigning a project to a CRO, the sponsor evaluates the facility through inquiry about scientific capability, technical infrastructure, regulatory track record, and capacity. The first impression is the audit before the audit.
Feasibility analysis & agreement.
Once enquiry closes successfully, feasibility analysis runs against capacity, timeline, scientific viability, and budget. If everything aligns, the project is confirmed and the master service agreement is signed.
Protocol preparation.
The CRO's medical writing team drafts the protocol per scientific requirements: study design (crossover, parallel, replicate), subject population, dose, sampling schedule, primary and secondary PK endpoints, statistical analysis plan, acceptance criteria.
Sponsor approval of protocol.
Drafted protocol is sent to the sponsor for review. If the protocol is sound and aligned with sponsor's regulatory strategy, sponsor approves. Iteration cycles here are common; sponsors with experienced regulatory teams catch upstream issues that save downstream cost.
DCGI & IEC approval.
The sponsor-approved protocol is submitted to the Drugs Controller General of India (DCGI) and Independent Ethics Committee (IEC) for regulatory and ethical clearance. Regional equivalents elsewhere: FDA + IRB (US), CHMP + ethics committees (EU), MHRA + ethics committees (UK), HPRA (Ireland).
Volunteer screening & recruitment.
Once protocol is regulatorily and ethically cleared, volunteer screening and recruitment begin. Inclusion/exclusion criteria, informed consent, screening labs, fitness assessment, randomisation. The clinical phase starts here.
Study conduct: dosing & sample collection.
Subjects are housed under controlled clinical conditions. Dose administration per protocol (single or multiple, fed or fasting). PK sample collection at pre-specified timepoints. Adverse event monitoring throughout.
Bio-analysis of samples.
Collected samples are transferred to the bioanalytical facility. Sample analysis runs against a validated method (LC-MS/MS or LBA, depending on the analyte). Calibration curves, QC samples, incurred sample reanalysis, run acceptance criteria all enforced per ICH M10.
PK & statistical analysis.
Bio-analytical concentration data is fed into the PK analysis software. Cmax, AUC, Tmax, t½ computed per subject. Statistical analysis runs the geometric mean ratio with 90% confidence interval against the 80–125% acceptance window (or scaled for highly variable drugs, narrowed for narrow therapeutic index drugs).
Draft report to sponsor.
After clinical, bioanalytical, and statistical analyses complete, the medical writing team assembles the draft clinical study report. The report passes through QC review (cross-check against protocol, raw data, statistical output) and QA review (compliance audit) before it is dispatched to the sponsor.
Report finalisation & dispatch.
Sponsor reviews the draft report and returns comments. The CRO addresses comments, finalises the report, and dispatches the final version with all annexures, raw data references, and audit trail.
Archival of study documents.
After dispatch, all trial-related documents are archived per sponsor and regulatory retention requirements. Typical retention: 15+ years for ANDA submissions, longer for MAA submissions. The archive is the inspection trail; if it's not in the archive, it didn't happen.
/ 02Where the flow fails.
The thirteen stages above are the happy path. Real studies break in predictable places. Three patterns the operationally-experienced CRO watches for:
- Stage 5 to 6 dropout — ethics or regulatory approval comes back with conditions that require protocol amendment. The amendment cycle delays recruitment by weeks. Sponsors with good regulatory teams pre-empt these by reviewing the protocol against recent regulator observations before submission.
- Stage 8 reanalysis cascades — bioanalytical run acceptance failures (calibration curve out of spec, QC failures, ISR failures) trigger reanalysis. Without strict run acceptance criteria documented before the study, reanalysis decisions become subjective and inspectable.
- Stage 10 QA findings — QA review surfaces deviations that should have been captured during stages 7–9. The earlier the deviation is captured, the easier the disposition. The later, the more expensive the remediation.
Reading this flow as a sponsor, the question to ask any CRO is not "do you do BA/BE?" — everyone says yes. The question is: at which of these thirteen stages have you most often encountered failure, and what is your standard recovery procedure? The honest answer tells you what kind of CRO you're working with.